Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Lightbox is small javascript library used to overlay images on top of the current page.
Prism is an extensible syntax highlighter.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.